High-power LEDs, e.g., using as much as 10 W and beyond in a single package, have become more widely used, and LEDs with even more power are expected in the future. Some of the electricity in the LED is converted into heat instead of light, and if the heat is not removed, the LEDs run at high temperatures. This lowers the LED's efficiency. Thus, thermal management of high power LEDs is an important issue. In some LEDs, Aluminium Nitride (AlN) is used on LED carrier because AN is a material with high thermal conductivity (>150 W/mK) and good electrical isolation (>10 kV/mm). But AlN is expensive and difficult for assembly because of brittle characteristics of the material.